Electronic devices in the context of this application are understood to mean what are called organic electronic devices, which contain organic compounds as functional materials. More particularly, these are understood to mean OLEDs.
The structure of OLEDs in which organic compounds are used as functional materials is described, for example, in U.S. Pat. Nos. 4,539,507, 5,151,629, EP 0676461 and WO 98/27136. In general, the term OLEDs is understood to mean electronic devices which have one or more layers comprising organic compounds and emit light on application of electrical voltage.
In electronic devices, especially OLEDs, there is great interest in improving the performance data, especially lifetime, efficiency and operating voltage. In these aspects, it has not yet been possible to find any entirely satisfactory solution.
A great influence on the performance data of electronic devices is possessed by layers having a hole-transporting function, for example hole-injecting layers, hole transport layers, electron blocker layers and emitting layers. For use in these layers, there is a continuous search for novel materials having hole-transporting properties, for example hole injection materials, hole transport materials, electron blocker materials and matrix materials, for use in combination with emitter materials, especially phosphorescent emitter materials.
For this purpose, the prior art describes, inter alia, monotriarylamines (cf. JP 1995/053955, WO 2006/123667 and JP 2010/222268) and bisfunctional or higher-functionality amines (cf. U.S. Pat. No. 7,504,163 and US 2005/0184657). Additionally known for this purpose are carbazole compounds, for example biscarbazolylbiphenyl (CBP) and the compounds described in WO 2008/086851, US 2005/0221124 A1, EP 2202818 A1 and WO 2013/060418. Additionally known for this purpose are bridged triarylamine compounds, as described, for example, in WO 2007/031165, WO 2010/083871, WO 2011/088877, WO 2011/107186 and WO 2011/128017.
However, there is an unchanged need for alternative compounds for this use.